Michael Reed Barratt is an American physician and a NASA astronaut. Board certified in internal and aerospace medicine, he served as a flight surgeon for NASA before his selection as an astronaut and has played a role in developing NASA's space medicine programs for both the Shuttle–Mir program and International Space Station. His first spaceflight was a long-duration mission to the International Space Station as a flight engineer on the Expedition 19 and 20 crew. In March 2011, Barratt completed his second spaceflight as a crew member of STS-133. Barratt made a second long-duration mission to the International Space Station as a flight engineer on the Expedition 70, 71, and 72 crew and also served as the pilot on the SpaceX Crew-8 mission.